Table 3.

Risk assessment

	Actual results
Test prediction	Develops psychosis	Does not develop psychosis	Total
At risk for psychosis	120	240	360
Not at risk for psychosis	80	560	640
Total	200	800	1000

Applying the same criteria to a help-seeking clinical population at a higher risk of a psychotic disorder will reduce the proportion of false-positive results. Assuming that in a clinical help-seeking population that the risk of psychosis is much higher than the general population risk, for example, 20 of every 100 individuals will ultimately develop schizophrenia or a psychotic mood disorder. This means that of 1000 individuals, 200 will develop a psychotic disorder and 800 will not. Assuming that the sensitivity of the at-risk criteria is 60%, this means that the criteria will correctly identify 120 but miss 80 individuals truly at risk. Assuming that the specificity is 60%, the test will correctly identify 560 individuals as not at risk, but will misclassify 240 individuals as at risk, even though they are truly not at risk.